PARIS, Nov 15 (Reuters) - The French will spend 19 billion euros ($21.5 billion) on online purchases over Christmas and the Black Friday to Cyber Monday sales days, lifting total online retail sales to over 90 billion euros for 2018, said the country's Fevad E-Commerce Federation.

The figures reflect growth in a sector that has seen Amazon make an entry, putting pressure on traditional retailers such as Carrefour to step up their online strategies with the French economy staging a gradual recovery.

The Black Friday discount sales day falls on November 23 and will be followed three days later by Cyber Monday.

Online retail sales during these four days alone could reach 1.3 billion euros, Fevad estimates.

This would lift total online retail sales in France to over 90 billion euros in 2018 from 81.7 billion in 2017.

In 2017, E-commerce represented 8.7 percent of overall French retail sales, up from 7.7 percent in 2016.

The overall French economy is forecast to grow 0.4 percent in the fourth quarter..